1. Field of the Invention
This invention relates to a detergent composition, and, more particularly, to a detergent composition comprising a phosphate-type surface active agent and an alkyl saccharide-type surface active agent. The detergent composition possesses a high foaming capability and is slightly irritative.
2. Description of the Background
Phosphate-type surface active agents impart less irritation to the skin than soaps, alkyl sulfates, or alkylether sulfate, and hence have widely been applied as body washing soaps and shampoos (Japanese Patent Publication No. 9033/1980 and Japanese Patent Publication No. 47959/1982).
Phosphate-type surface active agents, however, readily react to combine with calcium in water producing deposits of calcium phosphate, which impairs detergent capability, foaming capability, and the feeling upon use. This brings about the problem of an increased dry feeling to the hair and a powdery feeling to the skin.
In order to solve this problem the addition of a calcium ion chelating agent such as ethylenediamine tetraacetic acid (U.S. Pat. No. 4,303,556) and the addition of an amine oxide or betaine-type surface active agent as an insoluble surfactant-dispersing agent (Japanese Patent Laid-open No. 138594/1987, Japanese Patent Laid-open No. 74196/1984, and Japanese Patent Laid-open No. 103598/1983) have been proposed.
On the other hand, alkyl saccharides have been known as imparting only low irritation to the skin. Known alkyl saccharides include .beta.-alkyl saccharide such as octyl- or nonylglucoxide, decyl-, dodecyl-, or tridecylmaltoside, etc., and alkyl saccharides synthesized from a reduced sugar such as glucose, galactose, maltose, or the like and a higher alcohol (U.S. Pat. No. 3,219,656, U.S. Pat. No. 3,598,865, and U.S. Pat. No. 3,839,318).
These surface active agents, however, if used independently, pose problems of insufficient foaming capability and poor detergent capability. In addition, they impart dry, uncomfortable feeling when used as a detergent for washing hair or skin. For these reasons, use of these compounds as a detergent in combination with an anionic surface active agent (Japanese Patent Laid-open No. 130210/1984) or a nonionic surface active agent (Japanese Patent Laid-open No. 18594/1985) have been proposed.
Use of a phosphate-type surface active agent in combination with a chelating agent, however, does not bring about satisfactory effect. If used at a high concentration, the chelating agent increases irritativeness imparted by the detergent composition. Addition of a dispersing agent also entails problems of poor foaming capability, greater irritativeness, and insufficient detergent capability.
Also, no detergent compositions, providing low irritativeness, excellent detergent capability, and an acceptable feeling on use, have been developed through the use of alkyl saccharide-type surface active agents.
In view of this situation, the present inventors have undertaken extensive studies to obtain a detergent composition which is free from the above problems. As a result, the inventors have found the use of a specific of phosphate-type surface active agent in conjunction with a specific alkyl saccharide-type surface active agent causes insoluble phosphate salts to be solubilized or dispersed, increases detergent capability of the composition, enhances foaming capability, and decreases irritation to the hair or skin. These findings have led to the completion of this invention.